There are weeds, and then, there are noxious weeds. Just what is a “noxious weed?” These are plants that are listed on the Colorado Noxious Weeds List. They have been identified as being a threat to native species, usually because they are incredibly invasive. The list is divided into three sublists: lists A, B, and C. If a plant is on List A – it has been identified as a threat that is still possible to be contained and eradicated. We are legally required to eradicate these species if they show up on our property. An example of one that has shown up in residential landscapes in our area is myrtle spurge (Euphorbia myrsinites). List B species are generally too established to hope for eradication. Instead we try to contain them and stop their further spread. If you’re familiar with the plant called “butter and eggs” (Linaria vulgaris) then you’ve seen a List B plant. And List C plants are the ones that I joke are just too far gone – they’ve gotten too established and are too aggressive to eradicate and, possibly, to even contain. (Got bindweed (Convulvulus arvensis)? Then you have a List C noxious weed.) (more…)